Method for authenticating and charging a subscriber of a radio network

ABSTRACT

A subscriber to a wireless communications network is authenticated and charged for communication between subscriber&#39;s line equipment and the wireless communications network by using a mobile radio communications system including a mobile radio communications network and a mobile station belonging to the subscriber. Information identifying at least one of the subscriber and the mobile station is transferred via the subscriber&#39;s line equipment by the wireless communications network to the mobile radio communications network, or the mobile station sends the mobile radio communications network a signal, as a result of which the mobile radio communications network sends the mobile station a chargeable short message containing information for accessing the wireless communications network. The charge for the communication between the subscriber&#39;s line equipment and the wireless communications network is applied by charging for the short message in the mobile radio communications network. The operators of the wireless communications network and the mobile radio communications system are not involved in any additional investment in new modules.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based on and hereby claims priority to EuropeanApplication No. 02026272.1 filed on Nov. 26, 2002, the contents of whichare hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a method for authenticating a subscriber to afirst wireless communications network and for applying a charge to acommunication between a subscriber's line equipment and the firstwireless communications network by using a mobile radio communicationssystem.

2. Description of the Related Art

There is known to be a multiplicity of widely differing types oftelecommunications and data networks for communicating or transmittingdata. In this connection a distinction has to be made between twobasically different types of network. On the one hand there are themobile radio communications systems, such as those operating accordingto the standards known as GSM (global system for mobiletelecommunications) or UMTS (universal mobile telecommunicationssystem), in which mobile stations are authenticated and authorized uponregistering in the network concerned. The advantage of such networks isthat authentication also makes it possible to apply a charge for theservices used. In addition these networks, which are usually cellular,offer a high degree of mobility, since subscribers can move with theirmobile stations from one network cell to another. The disadvantage ofsuch cellular mobile radio communications systems is that the managementcosts are very high. In addition these systems provide the radiointerfaces to subscribers' mobile stations with only a relatively lowdata transfer rate.

In mobile radio communications systems, information such as speech,pictures, videos, short messages (SMS, short message service) or otherdata is transmitted between the sending and receiving stations over aradio interface with the aid of electromagnetic waves. Theelectromagnetic waves are emitted on carrier frequencies that lie withinthe intended frequency band for the system concerned. In this case aradio communications system includes subscriber stations, such as mobilestations, and base stations, such as B nodes, together with otherinstallations within the network itself. Thus the base stations and thenetwork installations form the mobile radio communications network. In aradio communications system the subscriber stations and the basestations are interconnected over a radio interface.

On the other hand there are networks designed as local area networks(LANs) or wireless local area networks (WLANs). Such networks providesubscribers' telephone stations with a form of access in which themanagement technology is very simple. A further advantage compared tomobile radio communications networks is the considerably higher datatransfer rate on the interfaces to subscribers' mobile stations. Thedisadvantage of such local area networks, however, is the lack of anyauthentication facility and thus of any facility to apply charges.

The term local area network usually refers to communication networksextending from a few tens of meters up to as much as ten kilometers.However, most LANs extend for only a few hundred meters within buildingsor organizations (in-house networks).

WLANs enable communication between for example a hard-wired networkinfrastructure and mobile computers (e.g. laptops). WLANs are often usedas extensions of hard-wired LANs in certain working environments. As arule WLANs include different access points (APs) which areinterconnected via a hard-wired LAN and in which data is transportedfrom a mobile transmitter via a radio link to the AP and then forwardedvia the LAN. Cells covered by WLANs have a diameter of up to one hundredmeters and are so small compared to the usual mobile radio cells thatthey are known as micro-cells.

Examples of the different standards for WLANs are HiperLAN, DECT, IEEE802.11, Bluetooth and WATM. However at the moment, particularly in theUSA and Europe, products based on the IEEE 802.11 family appear to begaining almost exclusive acceptance as wireless local area networks, tothe extent that the appropriate Ethernet connections are alreadyinstalled as standard in many computers and in portable computers suchas laptops, Notebooks and PDAs. Radio interfaces defined according tothe IEEE 802.11b standard for access to local area networks correspondfunctionally to a wired connection to local area networks (LANs), whichnowadays have become standard in offices. Interface cards for wirelessaccess to local area networks are also known as network interface cards(NICs). From the design point of view they are manufactured in the sameway as standard Ethernet cards and can be installed in modern operatingsystems by the method known as Plug & Play. It is no problem to fit theappropriate interface cards to portable computers if they have notalready been delivered ex-works with a built-in port for wired orwireless access to local area networks. In the case of the current andnext generation of operating systems (such as Windows XP fromMicrosoft), fully integrated support is provided for wireless local areanetworks (WLANs).

WLANs generally use the non-licensed frequency range around 2.4 GHz and5 GHz. Data transfer rates are up to 11 Mbit/s. Future WLANs could beoperated in the 5 GHz range and data transfer rates of over 50 Mbit/scould be achieved. Given current data rates of 11 Mbit/s and futurerates of 50 Mbit/s, the data transfer rates available to WLANsubscribers are significantly higher than those which can be offered bythe emerging, third generation of mobile radio communications systems(e.g. UMTS). For transferring large quantities of data, therefore,especially in combination with access to the Internet, access towireless local area networks (WLANs) is often preferred for highbit-rate connections.

WLANs are being used to an ever-increasing extent in hotels, airports,exhibitions and other places with high volumes of visitors. An importantfactor for the success of WLANs is the authentication and charging ofsubscribers. It is a disadvantage to wireless local area networks thatthey can offer no authentication facility for stations or computers notalready registered in the system. However, operators of WLANs inairports, for instance, need to make access available to many and variedsubscribers from widely differing regions. To be able to authenticatesubscribers, WLAN operators would have to enter into cross-licenseagreements with all possible internet service providers (ISPs), of whichthere are over 60,000 in Germany alone at the present time.

However, without a facility to authenticate subscribers or theirtelephone stations it is impossible to apply a charge for the servicesused in WLANs, since there is no way of knowing who should be billed.Access to wireless local area networks must therefore be offered eitherwithout payment or as a prepaid service charged to a credit card orsimilar.

For the operators of the mobile radio communications systems describedpreviously, these problems are very easily solved. Cellular mobile radiocommunications networks have a large number of mobile subscribers, whocan be authenticated. In addition these mobile radio communicationsnetworks have charging and billing systems. Using a method known asinternational roaming it is even possible to authenticate and servesubscribers who are registered with or subscribe to another mobile radiocommunications operator. Since nowadays a large proportion of consumersin the developed countries are mobile subscribers, mobile radiocommunications operators can in principle address almost every consumerthrough their own individual networks or through those of other mobilesystem operators.

There are many ways in which a mobile radio communications operator canintegrate a WLAN into its cellular mobile radio communications network.In the present state of discussions the basic distinction is betweentight and loose coupling. Tight coupling means complete UMTSintegration, that is, only physical layer of the WLAN is used, apartfrom which all the higher protocol layers are handled and optimized byUMTS. This solution is no longer under discussion, having turned out tobe technically difficult to accomplish and not very promising from thecommercial point of view.

In loose coupling two infrastructure-based variants are currently underpublic discussion, based on using either a registered identificationcard known as a subscriber identification module (SIM) or the protocolknown as remote access dial-in user access (RADIUS). In SIM-basedvariants a SIM card is installed in a Notebook or in a network accesscard dedicated to it. Typically the WLAN is regarded as a visitor localregister (VLR) of the mobile radio communications system, and is linkedto the mobile radio communications network by the mobile applicationpart (MAP) as it is known. Commercial success for the operators ofmobile radio communications networks is therefore heavily dependent onwhether in the future every card for accessing wireless local areanetworks will include a SIM card as standard. For this to happen itwould be necessary for computer manufacturers and the standardizationcommittees for data networks and telecommunications networks to developcommon standards, or a mobile radio communications operator would haveto subsidize this special type of NIC.

In the RADIUS variants the mobile radio communications network istypically regarded as an authentication, authorization and chargingserver of the WLAN, so that there is no need to modify the subscriberequipment in the WLAN.

In another approach, a WLAN subscriber enters his/her mobile subscriberISDN number (MSISDN) into a WLAN page composed in hypertext markuplanguage (HTML), and the WLAN transmits the information to the mobileradio communications system. The mobile radio communications system thensends a password by SMS to the mobile station of the WLAN subscriber,and this is used to control access to the WLAN. This procedure ensuresthat only those subscribers who also possess a valid subscription to themobile radio communications system receive access to the WLAN.

Particularly in terrestrial GSM mobile radio communications, theabbreviation SMS means a standardized service for the unidirectionaltransmission of messages with a limited length. Short messages are textmessages which do not exceed a defined maximum number of characters.

Though this facility solves the problem of authenticating WLANsubscribers, an effective method of charging must still be found. Amethod which has been suggested involves the charging information beingtransferred from the WLAN to a facility known as a wallet server andalso to the operator of the mobile radio communications system. Thelatter can be performed by coupling the WLAN to a micro-payment systemin the mobile radio communications network.

However, the charging methods described require the WLAN to be providedwith additional hardware. This approach therefore conflicts with theeconomic interests of the WLAN operator.

SUMMARY OF THE INVENTION

An object of the invention is to demonstrate a method of the kindinitially set out above, which enables the effective and inexpensiveauthentication and charging of a subscriber to a wireless communicationsnetwork by using a mobile radio communications system.

According to the invention, information identifying the subscriberand/or mobile station is transferred via the subscriber's line equipmentby the first wireless communications network to the mobile radiocommunications network, or the mobile station sends the mobile radiocommunications network a signal, as a result of which the mobile radiocommunications network sends the mobile station a chargeable shortmessage which contains information for accessing the first wirelesscommunications network, and the charge for the communication between thesubscriber's line equipment and the first wireless communicationsnetwork is applied via the charging procedure for the short message inthe mobile radio communications network.

The first wireless communications network constitutes in particular awireless local area network, that is, a WLAN. In principle, however, themethod can also be applied to other wireless communications networks.The signal which the mobile station sends to the mobile radiocommunications network is designed so that the mobile radiocommunications network recognizes that the subscriber is requestinginformation for accessing the first wireless communications network. Theshort message which the mobile radio communications network sends themobile station contains the access information as a minimum. It may alsohowever contain other information. The access information can be used bythe first wireless communications network for the purpose of decidingwhether the subscriber shall have access to this first wirelesscommunications network. Thus, the access information enables thesubscriber to communicate with the first wireless communications networkvia the subscriber's line equipment. The charge for the short message isapplied in the mobile radio communications network with the aid of asuitable charges account. This may be a charges account relating to thesubscriber, or it may relate to other charges accounts, possiblyincluding accounts defined for a group of subscribers, for example.

The method to which the invention relates exhibits a number ofadvantages:

-   -   The operator of the mobile radio communications system can        cost-effectively, that is at no additional expense, connect        WLANs from third-party providers to its in-house mobile radio        communications network.    -   Subscribers are accustomed to SMS-based user information, and        therefore need no conversion to a novel technology.    -   Any risk that the WLAN operator may send bills to persons who do        not exist is removed.    -   The one-time payment for the short message is a flat rate, which        as a rule is viewed as a desirable form of payment by        subscribers.    -   The desired WLAN service can be taken up as soon as the short        message is received.    -   The operator of the mobile radio communications system can use        the demand for services in the WLAN to test the demand for the        corresponding UMTS services that will be available in the        future.    -   The operators of the mobile radio communications system and the        WLAN are not involved in any additional investment in new        modules.    -   Subscribers show greater readiness to take up further chargeable        services via the same charging method. For example when a        subscriber has accessed the WLAN, certain Internet services can        be charged for by charging for another short message in the        mobile radio communications network. In this case therefore the        method of charging for a communication between the subscriber's        line equipment and the first wireless communications network is        performed again in respect of a particular communication, once        the subscriber has been authenticated in accordance with the        method to which the invention relates and a first charging        method to which the invention relates has taken place. The        access information then refers to the further chargeable service        requested by the subscriber. The method to which the invention        relates can thus if necessary be used repeatedly, producing a        graduation of charges.

In one embodiment of the invention, the short message is charged for inthe mobile radio communications network after the short message has beenreceived by the mobile station. In this case therefore charging isindependent of the use which the subscriber makes of the accessinformation. The charge can be applied to the appropriate chargesaccount as soon as the subscriber has received the chargeable shortmessage on his/her mobile station.

Advantageously, the charge for the short message within the mobile radiocommunications network is applied once the short message is opened. Inthis event, before the subscriber opens the short message a prompt canask whether he/she wishes to open this chargeable short message. Thiscan ensure that a subscriber does not have to pay charges for a shortmessage which he/she does not wish to use or look at, or did notintentionally request.

In a further embodiment of the invention, the short message is chargedfor in the mobile radio communications network once use has been made ofthe access information in the first wireless communications network.This ensures that the subscriber to the first wireless communicationsnetwork is only charged after using the access information to start acommunication with the first wireless communications network. In thiscase therefore the subscriber can have the mobile radio communicationsnetwork send a short message containing the access information withoutactually using it. In such an event no charge would be raised.

Advantageously, the information identifying the subscriber and/or themobile station can be the mobile station call number. In this way themobile radio communications network finds out directly the call numberto which the chargeable short message should later be sent. It is alsoconceivable for the name of the subscriber or an identification numbersuch as the international mobile subscriber identity (IMSI) to be sent,so that the mobile radio communications network can use this informationto determine the call number to which the chargeable short messageshould be sent.

In a preferred embodiment of the invention the mobile station sends themobile radio communications network the signal, using a call numberwhich belongs to the mobile radio communications network and is used forauthenticating and charging the subscriber to the first wirelesscommunications network. This may be a special call number which belongsto an intelligent network and which has been set up expressly for thepurpose of authenticating and charging within another wirelesscommunications network. From this special call number the mobile radiocommunications network recognises which requests the subscriber ismaking, namely the transfer of the chargeable short message containingthe identification information.

Advantageously, the call number is a free call number.

According to an embodiment of the invention the charge for the shortmessage depends on the service requested by the subscriber in the firstwireless communications network. Charging for the communication betweenthe subscriber's line equipment and the first wireless communicationsnetwork by charging for the short message in the mobile radiocommunications network corresponds to flat-rate charging for thecommunication between the subscriber's line equipment and the firstwireless communications network. Accordingly a higher charge for aservice requiring a high data transfer rate seems appropriate. As a rulethe charge for the short message containing the access informationshould be higher than a normal charge for other short messages sent inthe mobile radio communications system.

In a preferred embodiment of the invention the mobile radiocommunications network sends the access information to the firstwireless communications network. The first wireless communicationsnetwork can then compare the access information received from the mobileradio communications network with the access information of thesubscriber's line equipment and decide whether to allow the subscriberto access the first wireless communications network. It is also possiblefor both the mobile radio communications network and the first wirelesscommunications network to have a list of valid access information. Themobile radio communications network then selects an access informationfrom this list and sends it to the mobile station via the chargeableshort message.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and advantages of the present invention willbecome more apparent and more readily appreciated from the followingdescription of a typical embodiment, taken in conjunction with theaccompanying drawings of which:

FIG. 1 is a flowchart of a method to which the invention relates,

FIG. 2 is a block diagram of a mobile radio communications system, and

FIG. 3 is a block diagram of a wireless local area network and a mobileradio communications network.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings, wherein like reference numerals refer to like elementsthroughout.

This typical embodiment considers a subscriber who subscribes to amobile radio communications system. This subscriber is located, togetherwith a mobile station and a laptop, in the radio coverage area of aWLAN. The subscriber wishes to make use of the services provided by thelocal area network. Since the operator of the WLAN does not wish to makethe local area network available free of charge, it is necessary tocarry out a method for authenticating and charging the subscriber.

A flowchart of a method for authenticating and charging, to which theinvention relates, is shown in FIG. 1. At the start of the method thesubscriber has two options: one, in response to a prompt from the WLAN,is to advise the WLAN of his/her mobile call number (“Subscriber typesMSISDN into laptop”), whereupon the WLAN sends this number to the mobileradio communications system (“WLAN sends MSISDN”). By virtue of themessage from the WLAN, the mobile radio communications networkrecognizes that the subscriber is requesting access to the WLAN.

Alternatively, the subscriber can use his/her mobile station to dial thenumber of a special intelligent network (IN) service (“MS dials INnumber”). Nowadays mobile radio communications networks usually have anintelligent network which can be used to provide their mobile radiocommunications customers with supplementary services such as callforwarding to a speech mailbox. As a rule these systems have a serviceswitching point and a service control point. The former recognizes fromthe call number dialed that an IN service is being requested. The latterrecognises the desired service, enabling it to be provided and a chargeto be applied. Service control points are implemented on serverplatforms as a rule. By virtue of the number dialed, the mobile radiocommunications network recognizes that the subscriber is requestingaccess to the WLAN.

After receiving the information about the request for access information(“Received in PLMN”), the mobile radio communications network sends thesubscriber's mobile station a premium-rate SMS containing a one-timepassword for use in the WLAN (“Send premium-rate SMS with password”). Apremium-rate SMS is distinguished by its higher cost compared to anormal SMS. The cost charged to the subscriber for the premium-rate SMSis therefore increased compared to the normal cost for a SMS (e.g. 19Euro cents) by a charge corresponding to the service requested in theWLAN (e.g. 10 Euro per day for WLAN access). The subscriber thus paysonly a single charge for using the WLAN. There is no need to record thetime spent using the WLAN or the quantity of data transferred. It istherefore possible to do away with the charging systems which areotherwise normally used. However, with the aid of the IN number or bytransferring the MSISDN, it is possible to inform the mobile radiocommunications network which kind of service the subscriber wishes touse, so that the price of a premium-rate SMS can be varied according tothe service category.

Once the mobile station has received the premium-rate SMS (“SMS receivedin MS”), there are different options for the moment at which to applythe charge. In the simplest case charging can be carried out directlyafter receipt of the SMS (“Charge for SMS”). In this example thereforethe sum of 10.19 Euro is debited to the credit balance account assignedto the subscriber in the mobile radio communications system. Anotheroption is to apply the charge at the moment when the subscriber opensthe premium-rate SMS (“Open SMS”). This can also be linked to a securityprompt before the premium-rate SMS is opened, so that the subscriber ismade aware before opening the premium-rate SMS that an increased costwill be incurred on opening the short message. A further option is toapply the charge when the subscriber uses the password in the WLAN(“Type password into laptop”). In the latter case the WLAN must informthe mobile radio communications network that the password has been used.This can also be achieved if parts of the WLAN are also a component ofthe mobile radio communications system, so that there is no necessityfor the WLAN to inform the mobile radio communications network.

FIG. 2 shows a diagram of the flow between the mobile station MS and themobile radio communications network PLMN. The mobile station MS dialsthe appropriate number of the intelligent network IN, which is acomponent of the mobile radio communications network PLMN (“MS dials INnumber”). The mobile radio communications network PLMN accordingly sendsthe mobile station MS a premium-rate SMS containing a valid password forthe WLAN (“Send premium-rate SMS with password”). A facility SMSC (shortmessage service center) is involved in sending the SMS. The facilitySMSC handles the dispatch of short messages and forwards charginginformation about the short messages to a charging system in the mobileradio communications network PLMN. The mobile radio communicationsnetwork PLMN operates a credit balance account ACCOUNT for thesubscriber. The charge incurred for the premium-rate SMS is deductedfrom this credit balance account ACCOUNT (“Charge for SMS”).

To access the WLAN, the subscriber types into the laptop the passwordsent by the mobile radio communications network (“Type password intolaptop” in FIG. 1). The password can be entered with or without theMSISDN via an input mask on the laptop. The WLAN can then decide whetherto allow the subscriber to have access (“WLAN access control”).

FIG. 3 shows the computer LAPTOP, which is connected to a WLAN accesspoint AP by a radio link. In this instance, the computer LAPTOP standsfor any suitable subscriber's line equipment which is capable ofcommunicating with the wireless local area network by radio. The WLANhas a plurality of devices which are interconnected by radio or bylines. The devices include routers and bridges for distributing data toa plurality of subscriber's line equipment sets. The part of the WLANthat is connected by lines constitutes a LAN. The password is sent bythe computer LAPTOP by radio to the access point AP, from where it goesvia lines to an authentication unit AU.

The authentication unit AU compares the password received from thecomputer LAPTOP with information which has been sent to it by the mobileradio communications network PLMN. For this purpose the mobile radiocommunications network PLMN has a password service unit which sendsvalid passwords to the WLAN. The password service unit can generatethese passwords if necessary. Valid passwords can be sent to the WLANperiodically, for instance daily, or ad hoc, that is on request. Forexample a valid password list can be sent to the WLAN once a day. If apassword has been used, it is deleted from the list in the WLAN and inthe mobile radio communications network PLMN. The mobile radiocommunications network PLMN can thus send a password to the WLAN beforesending it to the mobile station MS, or even at about the same time,depending on the kind of coupling between the WLAN and the mobile radiocommunications system. The authentication unit AU may also be part of anappropriate IN service.

The authentication unit AU can clear an access control unit AC followingsuccessful authentication for the provision of a WLAN service. Theauthentication unit AU and the access control unit AC can be together onthe same platform or may be separate. Following clearance the computerLAPTOP can communicate with or through the WLAN, according to theservice requested.

The invention has been described in detail with particular reference topreferred embodiments thereof and examples, but it will be understoodthat variations and modifications can be effected within the spirit andscope of the invention.

1-9. (cancelled).
 10. A method for authenticating a subscriber to awireless communications network and for applying a charge tocommunication between subscriber line equipment of the subscriber andthe wireless communications network, by using a mobile station belongingto the subscriber and a mobile radio communications network, comprising:obtaining in the mobile communications network identifying informationfor at least one of the subscriber and the mobile station by one ofsending the identifying information via the subscriber line equipmentand the wireless communications network to the mobile radiocommunications network, and sending a signal from the mobile station tothe mobile radio communications network; receiving at the mobile stationa short message from the mobile radio communications network containingaccess information for accessing the wireless communications network;and applying a charge for the communication between the subscriber lineequipment and the wireless communications network, by charging for theshort message in the mobile radio communications network.
 11. A methodaccording to claim 10, wherein said applying charges for the shortmessage in the mobile radio communications network after the shortmessage has been received by the mobile station.
 12. A method accordingto claim 10, wherein said applying charges for the short message in themobile radio communications network after the short message has beenopened.
 13. A method according to claim 10, wherein said applyingcharges for the short message in the mobile radio communications networkafter the access information has been used in the wirelesscommunications network.
 14. A method according to claim 13, wherein theidentifying information for the at least one of the subscriber and themobile station is a first call number of the mobile station.
 15. Amethod according to claim 14, wherein said sending of the signal fromthe mobile station to the mobile radio communications network uses asecond call number which belongs to the mobile radio communicationsnetwork and is used for authenticating and charging the subscriber ofthe wireless communications network.
 16. A method according to claim 15,wherein the second call number is a free call number.
 17. A methodaccording to claim 16, wherein said applying the charge by charging forthe short message uses an amount based on a service of the wirelesscommunications network requested by the subscriber.
 18. A methodaccording to claim 17, further comprising sending the access informationfrom the mobile radio communications network to the wirelesscommunications network.